Almost everyone I know thinks that magnets are useless. Here, I will explain how they are not useless, and what they can be used for.
How do I get a magnet?
A magnet can easily be crafted at any level metalwork bench for an iron ingot and two black sand. Also, if you mine black sand with a golden spade, there is a chance you can get a magnet if you mine enough of it.
Can I make anything with a magnet?
Yes! You can make an electric motor, using 5 steel ingots, a magnet, and 10 copper wire at the level 2 metalwork bench.[B]
What does a magnet do?
If you click on an iron ore block with it, you will get 5 iron ore instead of the 3 you would normally get from mining it with a pickaxe. In addition, the iron ore block does not disappear, but becomes unmined stone. [I]Also, if you use it on black sand, the black sand will be instantly mined, without using any of the magnets durability.
[B]Can I use it on anything other than iron?
No, you cannot. It does not work on titanium or platinum either. Here are the test results for those ores:
If you try to use a magnet on another ore, it will be as if you used your hand.